Laxation of critically ill patients with lactulose or polyethylene glycol: a two-center randomized, double-blind, placebo-controlled trial

Abstract

Objective: To study whether lactulose or polyethylene glycol is effective to promote defecation in critically ill patients, whether either of the two is superior, and whether the use of enteral laxatives is related to clinical outcome.

Design: Double-blind, placebo-controlled, randomized study.

Setting: Two tertiary intensive care units.

Patients: Three hundred and eight consecutive patients with multiple organ failure were included when receiving mechanical ventilation and intravenous circulatory support and when defecation did not occur on day 3 after admission.

Interventions: Thrice daily administration of lactulose, polyethylene glycol, or placebo until defecation occurred, to a maximum of 4 days.

Measurements and main results: The number of patients with defecation during the study period was 32 of 103 (31%) for placebo, 76 of 110 (69%) for lactulose, and 70 of 95 (74%) for polyethylene glycol (p = .001 for lactulose and polyethylene glycol vs. placebo). Lactulose and polyethylene glycol-treated patients produced stools after a median of 36 and 44 hrs, respectively, compared with 75 hrs for the placebo group (p = .001 for lactulose and polyethylene glycol vs. placebo). Length of stay in the intensive care unit was a median of 156 hrs for the lactulose group, 190 hrs for the polyethylene glycol group, and 196 hrs for the placebo group (p = .001). Intestinal pseudoobstruction or Ogilvie's syndrome occurred in 4.1% of patients in the placebo group, 5.5% of patients in the lactulose group, and 1.0% of patients in the polyethylene glycol group. There was no difference in hospital mortality. Administration of morphine was associated with a longer time before first defecation, except in the polyethylene glycol group. For all groups, defecation within 6 days after admission was associated with a shorter length of stay.

Conclusions: Both lactulose and polyethylene glycol are more effective in promoting defecation than placebo. Patients receiving polyethylene glycol had a slightly lower incidence of acute intestinal pseudoobstruction, whereas length of stay was shorter in lactulose-treated patients. Morphine administration was associated with delayed defecation except in the polyethylene glycol-treated group. Irrespective of study medication, early defecation was associated with a shorter length of stay.